EP 999 764 describes a shoe with a sole extending from the heel region to the ball/toe region, the sole being formed by a sole body and a sole covering arranged on the underside of the sole body. Further, a recess extending from near the metatarsal region to the heel region is provided between the sole body and the sole covering. The portion of the sole region related to the recess forms a pivot element adapted for pivotal movement about an axis located in the end portion of the recess that is directed to the metatarsal region. The recess contains at least one approximately wedge-shaped or segment-shaped material element of a resilient, soft material. The pivotable sole covering is flexible in the region of the pivot axis and/or is tapered in this region.
The known shoe has proven disadvantageous in that due to the repeated pivotal movement of a part of the sole covering about the axis, the wear and tear are relatively great in the metatarsal region, which consequently is a weak point of this shoe. Besides, this is no wonder, since this very region, where the pivot axis of the sole covering is located, is exposed to particularly great stresses at each step. Every step, the sole covering is first put down in the heel region; then, the shoe is rolled off in and through the metatarsal region which takes place especially in the region of the pivot axis of the flexible sole portion
In an embodiment of the known shoe, the approximately wedge-shaped, lens-shaped or approximately segment-shaped recess is filled with resilient foam material which effects a relief of the foot and/or knee joint. The foam material becomes brittle over time due to the constant high stress it is exposed to, it becomes sensitive to mechanic influences and absorbs any kind of liquid, with the consequence that this foam material has to be removed and replaced with new damping material in a time-consuming operation.